From: Andi Kleen <ak@muc.de>
Check first before calling profile_pc() and doing other complicated checks
if profiling is enabled. This saves a few cycles in the profile tick and
protects the average user against potential bugs in profile_pc.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/kernel/profile.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff -puN kernel/profile.c~optimize-profile-path-slightly kernel/profile.c
--- 25/kernel/profile.c~optimize-profile-path-slightly Tue Oct 5 16:15:07 2004
+++ 25-akpm/kernel/profile.c Tue Oct 5 16:15:07 2004
@@ -381,12 +381,10 @@ static int __devinit profile_cpu_callbac
#define profile_flip_buffers() do { } while (0)
#define profile_discard_flip_buffers() do { } while (0)
-void profile_hit(int type, void *__pc)
+inline void profile_hit(int type, void *__pc)
{
unsigned long pc;
- if (prof_on != type || !prof_buffer)
- return;
pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
atomic_inc(&prof_buffer[min(pc, prof_len - 1)]);
}
@@ -396,6 +394,8 @@ void profile_tick(int type, struct pt_re
{
if (type == CPU_PROFILING)
profile_hook(regs);
+ if (prof_on != type || !prof_buffer)
+ return;
if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask))
profile_hit(type, (void *)profile_pc(regs));
}
_